|Dear Mr. Chairman:
The American Dental Association (ADA)
has endorsed fluoridation of community water systems for 50 years as a
safe and effective way to prevent tooth decay. Fluoride is nature's cavity
fighter, occurring naturally in the earth's crust, in combination with
other minerals in rocks and soil. Small amounts of fluoride occur naturally
in all foods and beverages. Water fluoridation is the process of adjusting
natural level of fluoride to a concentration sufficient to protect against
tooth decay, a range of from 0.7 parts per million (ppm) to 1.2 ppm.
Thanks in large part to community water
fluoridation, half of all children ages 5 to 17 have never had a cavity
in their permanent teeth. According to the April 2000 Journal of Dental
Research, the use of fluorides in the past 40 years has been the primary
factor in saving some $40 billion in oral health care costs in the United
Just last month, Surgeon General David
Satcher wrote in his report, Oral Health Care in America, "Community
water fluoridation is safe and effective in preventing dental caries in
both children and adults. Water fluoridation benefits all residents served
by community water supplies regardless of their social or economic status."
Revised national health objectives
in Healthy People 2010 again include objectives to improve the nation's
oral health. Oral Health Objective 9 states that at least 75% of the population
should be receiving the benefits of optimally fluoridated water by the
year 2010. According to the most recent Centers for Disease Control and
Prevention (CDC) Fluoridation Census, only 62% of the population served
by public water systems has access to fluoridated water.
After 50 years of research and practical
experience, the preponderance of scientific evidence indicates that fluoridation
of community water supplies is both safe and effective. Methods and populations
differ, but studies show that water fluoridation can reduce decay in baby
teeth by as much as 60% and can reduce tooth decay in permanent teeth by
Even before the first community fluoridation
program began in 1945, epidemiological data from the 1930s and 1940s revealed
lower decay rates in children consuming naturally occurring fluoridated
water compared to children consuming fluoride-deficient water.
Since that time, innumerable studies
have been conducted to demonstrate the safety and/or effectiveness of water
fluoridation. Three outstanding reviews of community water fluoridation
Newbrun E. Effectiveness of water fluoridation.
J Public Health Dent 1989;49(5):279-89. (Results of 113 studies in 23 countries
Ripa LW. A half-century of community water
fluoridation in the United States: review and commentary. J Public Health
Dent 1993;53(1):17-44. (Analysis of fifty-year history of community water
Numerous large-scale epidemiological studies
of water fluoridation have been conducted, making fluoridation one of the
most widely studied public health measures. Because these large investigations
have been consistently validated, water fluoridation is not as frequently
studied as in past decades. Water fluoridation is a perfect example of
how well designed studies stand the test of time and scientific scrutiny.
Studies included in the review articles listed continue to be referenced
today and have become "classics" in the public health field.
Murray JJ. Efficacy of preventive agents
for dental caries. Caries Res 1993;27(Suppl 1):2-8. (Review of studies
conducted from 1976 through 1987.)
Many well-documented studies have compared
the decay rates of children before and after fluoridation in the same community,
as well as with children in naturally fluoridated and/or nonfluoridated
communities. Because of the high geographic mobility of our populations
and the widespread use of fluoride toothpastes, supplements and other topical
agents, such comparisons are becoming more difficult to conduct.
Although other forms of fluoride are
available, persons in nonfluoridated communities continue to demonstrate
higher dental decay rates than their counterparts in communities with water
fluoridation as determined in the following studies:
Brunelle JA, Carlos JP. Recent trends
in dental caries in U.S. children and the effect of water fluoridation.
J Dent Res 1990;69(Spec Iss):723-7. (Review of 1987 survey of 40,000 school
children compared to survey in 1979-80.)
Horowitz HS. The effectiveness of community
water fluoridation in the United States. J Public Health Dent 1996 Spec
Iss;56(5):253-8. (Review of fifty years of water fluoridation.)
The safety and/or effectiveness of community
water fluoridation have been examined not only in communities within the
US, but also in other communities worldwide. Below are several international
studies of community water fluoridation:
Selwitz RH, Nowjack-Raymer RE, Kingman
A, Driscoll WS. Dental caries and dental fluorosis among schoolchildren
who were lifelong residents of communities having either low or optimal
levels of fluoride in drinking water. J Public Health Dent 1998;58(1):28-35.
(Review of tooth decay experience between children who were lifelong residents
of optimally fluoridated communities versus those who were lifelong residents
of communities having low fluoride levels in drinking water.)
Fluoride, teeth and health. Royal College
of Physicians. Pitman Medical, London;1976. (There is no evidence of a
relationship between water fluoridation and congenital malformations, thyroid
disorders, cancers or allergies.)
Knox EG. Fluoridation of water and cancer:
a review of the epidemiological evidence. Report of the Working Party.
London: Her Majesty’s Stationary Office;1985. (Neither fluoride occurring
naturally in water, nor fluoride added to water supplies, is capable of
inducing cancer, or of increasing the mortality from cancer.)
Spencer AJ, Slade GD, Davies M. Water
fluoridation in Australia. Comm Dent Health 1996;13(Suppl 2):27-37. (Water
fluoridation is the most effective and socially equitable means of achieving
community wide reductions in dental decay.)
Mr. Chairman, community water fluoridation
plays an important role in the health of infants and toddlers. Early childhood
caries (ECC) is a serious socio-behavioral and dental problem that afflicts
infants and toddlers in many communities and populations in the United
States and other countries. The condition reaches epidemic proportions
in low-income and Native American communities in the US. Known also as
baby bottle tooth decay or nursing bottle mouth, the condition is characterized
by severe decay, especially in the upper front teeth, which can result
in tooth loss in infants and toddlers. Water fluoridation has been identified
as the most highly recommended preventive strategy for early childhood
World Health Organization. Fluorides and
oral health. Report of a WHO Expert Committee on Oral Health Status and
Fluoride Use. WHO Technical Report Series 846. Geneva;1994. (Water fluoridation
is the most effective method of reaching an entire population so that all
social classes benefit without the need for active participation on the
part of individuals. It is essential that water fluoridation have the support
of the leading health authorities and of the government.)
From time to time, the safety and effectiveness
of water fluoridation has been questioned. None of these charges has ever
been substantiated by generally accepted science. It is important to review
information about fluoridation with a critical eye.
Ismail AI. Prevention of early childhood
caries. Community Dent Oral Epidemiol 1998;26(Suppl 1):49-61. (Water fluoridation
provides the only means of ECC prevention that does not require a dental
visit or parental motivation.)
Recently, extensive investigative reports
found no scientific evidence that exposure to fluoride at the levels found
in optimally fluoridated water presents any risk for the development of
any disease process.
There have been claims that exposure
to fluoride presents a neurotoxic (harmful or damaging to nerve tissue)
risk or lowered intelligence. Such claims are based on a 1995 study (Mullenix
PJ, Denbesten PK, Schunior A, Kernan WJ. Neurotoxicity of sodium fluoride
in rats. Neurotoxicol Teratol 1995;17(2):169-77) in which rats were fed
fluoride at levels up to 125 times greater than that found in optimally
fluoridated water. The study attempted to demonstrate that rats fed extremely
high levels of fluoride (75 ppm to 125 ppm in drinking water) showed behavior-specific
changes related to cognitive deficits. These amounts are far in excess
of the U.S. Public Health Service recommended fluoride levels of 0.7 to
1.2 ppm in water systems.
In addition, the experiment also studied
the offspring of rats who were injected two to three times a day with fluoride
during their pregnancies in an effort to show that prenatal exposure resulted
in hyperactivity in male offspring. Independent scientific review of this
finding did not support the conclusions made by the authors and discounts
the potential of sodium fluoride as a potential neurotoxicant. (Ross JF,
Daston GP. Neurotoxicology and Teratology 1995;17(6):685-6.) (Whitford
GM. The metabolism and toxicity of fluoride, 2nd rev. ed. Monographs in
oral science, Vol. 16. Basel, Switzerland: Karger;1996.)
Other studies attempted to link fluoride
exposure to direct effects of the brain. One such 1998 study raised concerns
about potential relationships between aluminum-fluoride and sodium-fluoride
and Alzheimer's disease. (Varner JA, Jensen KF, Horvath W, Isaacson RL.
Chronic administration of aluminum-fluoride or sodium-fluoride to rats
in drinking water: alterations in neuronal and cerebrovascular integrity.
Brain Res 1998;784:284-98.) Upon further review by other scientists, the
study was found to contain major flaws in the experimental design, making
it impossible for any definitive conclusions to be drawn. (American Dental
Association, Health Media Watch: Study linking fluoride and Alzheimer’s
under scrutiny. J Am Dent Assoc 1998;129:1216-8). The study also conflicts
with the position of the Alzheimer's Disease Foundation, which states that
there is little evidence to suggest that aluminum has a causative role
in the disease.
Another study related to the comparison
of fluoridated versus non-fluoridated communities in upstate New York (Schlesinger
ER, Overton DE, Chase HC, Cantwell KT. Newburgh-Kingston caries-fluorine
study XIII: pediatric findings after ten years. J Am Dent Assoc 1956;52:296-306).
The original study noted a five-month difference in the average age of
menarche between girls from the two cities, which the authors indicated
as "not statistically significant."
One risk that has been attributed to
water fluoridation is the possible formation of very mild dental fluorosis
on permanent teeth in about 13% of children. Dental fluorosis is not a
health effect; it is a cosmetic effect usually unnoticeable by untrained
examiners. Mild dental fluorosis is characterized by nearly imperceptible
white flecks in the enamel of permanent teeth. The risk of dental fluorosis
can be greatly reduced by simple steps and without denying children the
benefits of water fluoridation.
In 1997, the Food and Nutrition Board
of the Institute of Medicine developed a comprehensive set of reference
values for dietary nutrient intakes. These new reference values, the Dietary
Reference Intakes (DRI), replace the Recommended Dietary Allowances (RDA)
that had been set by the National Academy of Sciences since 1941. The new
values present nutrient requirements to optimize health and, for the first
time, set maximum-level guidelines to reduce the risk of adverse effects
from excessive consumption of a nutrient. Along with calcium, phosphorous,
magnesium and vitamin D, DRIs for fluoride were established because of
its proven effect on tooth decay.
Mr. Chairman, the ADA's policies regarding
community water fluoridation are based on generally accepted scientific
knowledge. This body of knowledge is based on the efforts of nationally
recognized scientists who have conducted research using the scientific
method, have drawn appropriate balanced conclusions based on their research
findings and have published their results in peer-reviewed professional
journals that are widely held or circulated. Confirmation of scientific
findings also reinforces the validity of existing studies.
With the advent of the Information
Age, a new type of "pseudo-scientific literature" has developed. The public
often sees scientific and technical information quoted in the press, printed
in a letter to the editor or distributed via an Internet Web page. Often
the public accepts such information as true simply because it is in print.
Yet the information is not always based on research conducted according
to the scientific method, and the conclusions drawn from research are not
always scientifically justifiable. In the case of water fluoridation, an
abundance of misinformation has been circulated. Therefore, scientific
information from all print and electronic sources must be critically reviewed
before conclusions can be drawn.
We have attached a copy of the ADA'
s recent publication Fluoridation Facts to provide additional information
concerning the safety and effectiveness of community water fluoridation.
Nearly 100 national and international organizations recognize the public
health benefits of fluoridation for preventing dental decay. We would appreciate
your including this along with our letter in the hearing record.
|Richard F. Mascola, D.D.S.
|John S. Zapp, D.D.S.